R4DS CH5

library(tidyverse)
install.packages('nycflights13')

Installing package into <U+393C><U+3E31>C:/Users/clylo/Documents/R/win-library/3.5<U+393C><U+3E32>
(as <U+393C><U+3E31>lib<U+393C><U+3E32> is unspecified)
trying URL 'https://cran.rstudio.com/bin/windows/contrib/3.5/nycflights13_1.0.0.zip'
Content type 'application/zip' length 7110229 bytes (6.8 MB)
downloaded 6.8 MB

package ‘nycflights13’ successfully unpacked and MD5 sums checked

The downloaded binary packages are in
    C:\Users\clylo\AppData\Local\Temp\RtmpK4rZI8\downloaded_packages

library(nycflights13)
flights

filter(flights, month==1,day==2)

Had an arrival delay of two or more hours

filter(flights,arr_delay > 2)

Flew to Houston (IAH or HOU)

filter(flights,dest == "IAH" | dest == "HOU")

Were operated by United, American, or Delta

unique(flights["carrier"])

filter(flights, carrier == "DL"| carrier == "UA"| carrier == "AA")

Departed in summer (July, August, and September)

filter(flights,month >= 7 ,month <=9)

Arrived more than two hours late, but didn’t leave late

filter(flights, arr_delay > 2, dep_delay <= 0)

Were delayed by at least an hour, but made up over 30 minutes in flight

filter(flights, dep_delay >= 1, dep_delay - arr_delay > 30)

Departed between midnight and 6am (inclusive)

filter(flights, sched_dep_time <= 600 | sched_dep_time == 2400 )

2. between() returns if values fall between a range

filter(flights, between(sched_dep_time, 0,600))

filter(flights,is.na(dep_time))

Probably cancellations

4. anything to power 0 equals one so not NA

NA^0

[1] 1

5.3.1 1.

arrange(flights, desc(is.na(dep_time)),dep_time)

arrange(flights, desc(dep_delay))

arrange(flights,air_time)

arrange(flights,desc(air_time))

5.4.1 1.

select(flights, dep_time, dep_delay, arr_time, arr_delay)

select(flights,dep_time:arr_time, arr_delay)

select(flights, contains("delay"), contains("time"))

select(flights, arr_time, arr_time)

nothing

vars <- c("year", "month", "day", "dep_delay", "arr_delay")
select(flights,one_of(vars))

one_of matches variable names to those stored in a vector, nice!

select(flights,contains("TIME", ignore.case = FALSE))

yes b/c its not case sensitive just like sql lol

5.5.2 1.

View(flights)
#mutate(flights,  = dep_time)